In the past, a system has been suggested, which causes two video cameras provided at the right and left to simultaneously capture images of a subject, and displays a three-dimensional image by simultaneously outputting the obtained two types of images (right eye image and left eye image). However, when the two video cameras are used, the size of the apparatus increases, which is not practical. A base line length between the two video cameras, i.e., a distance between both eyes as a three-dimensional camera, is often set at about 65 mm corresponding to the distance between both eyes of a person regardless of a zoom ratio of the lenses. In such case, in a zoomed-up image, parallax between both eyes increases, and this forces the optical system of an observer to perform information processing that is different from ordinary processing, and this becomes a cause of visual fatigue. When a moving subject is captured by two video cameras, it is necessary to perform precise synchronization control of the two video cameras, which is extremely difficult, and it is also extremely difficult to precisely control a convergence angle.
In order to facilitate adjustment of a lens system for three-dimensional shooting, a three-dimensional shooting apparatus has been suggested, which shares the same optical system by combining polarization filters for polarization in directions perpendicular to each other (for example, see Japanese Patent Application Publication No. H6-054991).
A method has been suggested, in which three-dimensional shooting is performed by an image-capturing apparatus including two lenses and image-capturing means (for example, see Japanese Patent Application Laid-Open No. 2004-309868). The image-capturing apparatus disclosed in this Japanese Patent Application Laid-Open includes: image-capturing means in which pixels corresponding to an integral multiple of a predetermined number of scan lines are provided on an image-capturing surface; a first horizontal component polarization means for passing a horizontal component of a first video light from a subject; and a first vertical component polarization means which is provided at a position away from the first horizontal component polarization means by a predetermined distance, and which passes only a vertical component of a second video light from the subject, wherein the horizontal component that is passed by the first horizontal component polarization means is condensed onto pixels of a predetermined range on the image-capturing surface, and the vertical component that is passed by the first vertical component polarization means is condensed onto pixels of in a remaining range except the predetermined range. More specifically, the horizontal component polarization filter and the vertical component polarization filter spaced apart with an interval corresponding to parallax of a person are provided with two lenses at positions away from each other by a predetermined distance from the image-capturing surface of the CCD.